There have been proposed several apparatuses for deciding the presence of a mobile object in a specific area using a motion detection sensor such as a pyroelectric sensor.
For example, PTL 1 discloses an apparatus for deciding the intrusion and leaving of a mobile object by providing different detection areas with respective corresponding detector elements, and deciding the intrusion and leaving from the temporal relations of detected signals output by the detector elements. PTL 2 discloses an apparatus that starts a timer counter when motion is no longer detected by a human body sensor, and turns off an electric device after a certain period of time has passed.